During President Harry S. Truman’s administration, the White House was found to be structurally unsound. Under Truman’s recommendation, the residence underwent major renovation. From 1948 to 1952, construction workers tore down the entire interior, retaining only the third floor and the original outer walls that architect James Hoban built. Using steel instead of wood, workers reinforced the building, adding several rooms, and restoring the existing rooms to their original appearance.